Discussion-OBS Weekend Feb 8-9 Another mainly 12 hour snow-ice event possibly changing to rain before ending Sunday. NYC-LI-S of I78 on the edge?

[Sharknado123]

16 minutes ago, ILoveWinter said:

? It was not BS, my window faces a small park and the ground was certainly covered enough to indicate a half inch. 

I agree, anybody who was not within the five boroughs for this event does not get to have an opinion on whether a measurement was BS or not.

[psv88]

I think there was a widespread 1/2” of slop today across the city and coast. No real gradient, so I believe the .5”. It’s what we had out here too 

[EastonSN+]

Anyone have the latest EPS or gefs for the storm? Further north or south of the ops? Happy to accept negative affirmation if no one has checked.

[mikem81]

Just now, EastonSN+ said:

Anyone have the latest EPS or gefs for the storm? Further north or south of the ops? Happy to accept negative affirmation if no one has checked.

GEFS is north of 6z and EPS similar to 6z which was pretty south of 0z

[Snowlover11]

keep today’s storm outta this thread.  post in the correct threads.

[RU848789]

4 hours ago, LibertyBell said:

Yeah that 5-8 prediction by TWC for here was pretty shocking

I was quite surprised, since they've often gone with the GFS and did that famously for the Jan-15 bust for our area, where they were the only ones predicting around a foot or so for NYC metro (per the GFS) vs. the 20-30" predicted by the NWS and others (likely following the euro which never wavered for days, but was wrong, as the storm was essentially displaced 70 miles east of the forecast).  But the GFS is the least snowy model for this weekend, so not sure what they're following or if they make completely original forecasts now.  

[RU848789]

4 hours ago, mikem81 said:

MJO always love your enthusiasm, but please dont post 10:1 maps as it was way off for this morning on the Hrrr. Kuchera only.. looks similiar for this storm other than the coast literally

Sorry, but Kuchera often sucks, as it uses a very crude algorithm based only on max column temp and ignores crystal growth parameters that "create" snow ratios.  I much prefer 10:1, so I know exactly how much QPF goes into the calculation and can adjust easily low or high from that number based on other factors.  Kuchera can be useful close to an event when column temps and snow growth parameters are much better known.  The HRRR, RAP and some other models were high because they assumed snow and we got sleet at 2-3:1, which has a far lower ratio than Kuchera or obviously 10:1 snow - precip type is way more important than snow ratio estimates in this case.  Also, if we knew most of the QPF was going to be sleet, it would've been a simple ~3 to 1 conversion to estimate the sleet accumulation vs. the 10:1 accumulation, whereas that would be very difficult with Kuchera.  

[White Gorilla]

Winter Storm Watch for Sat night into Sunday morning up here.  Hope all of you get it.  

[Yanksfan]

I just got a watch myself. 

[Snowlover11]

WSW 4-7”

[JonClaw]

Upton's going with 2-4" for the City with a trace of ice.

[Stormlover74]

Snow into the city by 4pm Saturday on the nam

[MJO812]

Wait what

Winter Storm watch for NYC. 2-4 inches of snow and some ice.

[BoulderWX]

1 minute ago, MJO812 said:

Wait what

Winter Storm watch for NYC. 2-4 inches of snow and some ice.

Yup, Upton hoisted early. Seems like a fair call for now. 

[EastonSN+]

[Allsnow]

 

[MJO812]

Nam is slightly more north but a good thump. 

[NEG NAO]

Winter Storm Watch issued for Saturday Night into Sunday NYC Metro

WSW from KOKX

[jm1220]

3 minutes ago, NEG NAO said:

Winter Storm Watch issued for Saturday Night into Sunday NYC Metro

WSW from KOKX

I'm surprised, maybe hedging if the low chance the southern solution like NAM happens. 

[Allsnow]

10 minutes ago, jm1220 said:

I'm surprised, maybe hedging if the low chance the southern solution like NAM happens. 

18z nam is north but both are showing a chance at a thump before a changeover. I actually like your area for this storm if the transfer goes as forecasted currently 

[LibertyBell]

9 minutes ago, jm1220 said:

I'm surprised, maybe hedging if the low chance the southern solution like NAM happens. 

this will likely go to a winter weather advisory for us, they already shaved an inch off the earlier projection of 3 inches for JFK

[EastonSN+]

3 minutes ago, LibertyBell said:

this will likely go to a winter weather advisory for us, they already shaved an inch off the earlier projection of 3 inches for JFK

Do you know what the sleet and ice winter storm warning parameters are? I was curious as all I know is 6 in of snow and sleet. Wondering if you can have a winter storm warning if you had say three inches of snow and a 10th of an inch of ice.

[ILoveWinter]

Weird that they'd go for a Watch in the immediate metro this early if they are only forecasting 2-4

[dmillz25]

1 minute ago, ILoveWinter said:

Weird that they'd go for a Watch in the immediate metro this early if they are only forecasting 2-4

The ice factor

[LibertyBell]

2 minutes ago, EastonSN+ said:

Do you know what the sleet and ice winter storm warning parameters are? I was curious as all I know is 6 in of snow and sleet. Wondering if you can have a winter storm warning if you had say three inches of snow and a 10th of an inch of ice.

For ice storm warnings I think it's half an inch of ice though not completely sure.

There is no separate warning for sleet as the totals are integrated into snowfall totals. 2-3:1 ratio.

WWA begins at 1 inch here.

3 inches of snow and 0.1 ice would be WWA (I think) BUT 4 inches of snow + some ice would be a WSW (I've seen WSW for 4-6 inches of snow before.)

4-6 inches is the minimum for WSW from what I've seen.

 

[jm1220]

5 minutes ago, EastonSN+ said:

Do you know what the sleet and ice winter storm warning parameters are? I was curious as all I know is 6 in of snow and sleet. Wondering if you can have a winter storm warning if you had say three inches of snow and a 10th of an inch of ice.

It's 0.25" freezing rain or higher, 6" in 12 hours or 8" in 24 hours. Sleet/snow are counted as the same. 

[LibertyBell]

2 minutes ago, ILoveWinter said:

Weird that they'd go for a Watch in the immediate metro this early if they are only forecasting 2-4

watches can go to either advisories or warnings

[LibertyBell]

Just now, jm1220 said:

It's 0.25" freezing rain or higher, 6" in 12 hours or 8" in 24 hours. Sleet/snow are counted as the same. 

ah so not half an inch of ice.

as far as WSW are concerned, I've seen them with forecast totals as low as 4-6.

 

[Krs4Lfe]

Although I'm not sure what the official criteria is, it's usually if there is 5-6+ of snow being forecast for NYC within a 12 hour period. However, in February 2014, right on the heels of a 7-8 inch snowstorm after super bowl, there was a storm a few days later and the forecast was for 4-5" of snow, and then there was like 0.1-0.15 of freezing rain to finish off, so there was a winter storm warning for that event. However, in late February 2021, there was 5" of snow followed by some ice, but that was a multi-wave storm, so there was snow that Thursday morning, freezing rain in afternoon and overnight, then a few inches of snow the day after (Friday.) But since that was a 24+ hour event, there was only a winter weather advisory for it. February 2018 and March 2019 also had winter storm warnings for 5-6" forecast for NYC within a 10 hour period or so. So it depends on the duration and the amount. Generally speaking, 5-6"+ is required for winter storm waring for NYC unless it falls within 12 hours or less or if there is a combo of snow/freezing rain 

[SnowGoose69]

3 minutes ago, dmillz25 said:

The ice factor

I think its more the concern that 6 inches is a possibility, albeit a low one.  That said, to me a watch was more warranted on the event 2 weeks ago at this range than it is here.